Gaviotin Antártico

DESCRIPTION:
Length: 39 - 41 cms.
Very similar to South American Tern (Tern). It differs by having shorter legs, thin and being a little kid. It is possible that both races they encounter in the extreme south, but there is a curiosity: does not move north on the Pacific side, instead goes to Brazil on the Atlantic side.
Very difficult to differentiate in the middle.